JP5989132B2 - Cutting tool and method for removing cutting insert from cutting tool - Google Patents

Description

Field of Invention
[001] The subject of the present application relates to a grooving and parting-off cutting tool of the kind in which a cutting insert is detachably fixed to a holder blade by means of an elastic clamping force.

Background of the Invention
[002] A grooving and parting cutting tool in which the cutting insert is detachably fixed to the holder blade by an elastic clamping force can be removed from the holder blade using a key.

  [003] An example of such a clamping mechanism is disclosed in US Pat. No. 7,524,147.

  [004] Examples of such cutting inserts and keys are disclosed in US Pat. Nos. 7,313,096, 5,795,109, 6,454,498, and 6,565,292.

  [005] It is an object of the subject matter of the present application to provide a cutting tool having improved means for elastically clamping a cutting insert within an insert receiving pocket of a holder blade.

  [006] It is also an object of the subject matter of the present application to provide a cutting tool with improved means for removing a cutting insert from a holder blade.

Summary of the Invention
[007] According to the subject matter of the present application, a cutting tool is provided, comprising a holder blade and a cutting insert elastically clamped in the holder blade, the holder blade having a body portion and a holding portion; A holding tool has a cutting tool having two opposing side surfaces,
An insert receiving slot having a holder longitudinal axis that opens to the holder front end surface of the holder blade and extends in the front-rear direction;
A holder passage extending along the holder passage axis and opening in at least one of the two side surfaces, wherein the holder passage axis includes a holder passage center point;
The insert receiving slot has a base jaw lower surface facing upward, and the base jaw lower surface includes at least one longitudinally extending base jaw clamp portion, each base jaw clamp portion being parallel to the holder longitudinal axis. Holder contains virtual straight lines,
The holder passage center point is located below the lower surface of the base jaw,
The cutting insert has an insert longitudinal axis parallel to the holder longitudinal axis,
Including opposing insert upper and lower surfaces with a peripheral surface extending therebetween, including a cutting edge coupled to the upper surface of the insert, the peripheral surface including two opposing outer surfaces;
The insert passage extends along the insert passage axis and opens in opposite outer surfaces, the insert passage axis includes an insert passage center point;
The lower surface of the insert includes at least one longitudinally extending lower clamp portion, and each lower clamp portion includes an insert virtual straight line parallel to the insert longitudinal axis,
At least one lower clamp part is in clamping contact with at least one base jaw clamp part, and the cutting insert is located at the rearmost position in the insert receiving slot and defines the assembled state. ,
The passage plane including the holder passage axis and the insert passage axis is perpendicular to the insert longitudinal axis and forms a first angle with the main plane including the insert passage axis;
The first angle is 60 ° or less.

[008] Also according to the subject matter of the present application, there is provided a method of removing a cutting insert from a cutting tool with a removal key;
The insert receiving slot includes a clamp jaw upper surface facing the base jaw lower surface,
The cutting insert is elastically clamped between the clamp jaw upper surface and the base jaw lower surface,
The ejection key has at least one protrusion, the at least one protrusion including first and second engagement portions and a single pivot.
The method
Positioning the removal key with respect to the cutting tool such that the first and second engagement portions are simultaneously engaged with the holder passage and the insert passage, respectively, and the pivot is located in the holder passage;
Rotating the removal key in one direction about the pivot and applying a removal force to the cutting insert in the forward direction.

Brief Description of Drawings
[009] To better understand the present application and to show how it is implemented, reference is now made to the following accompanying drawings.

1 is a perspective view of a cutting tool according to a first embodiment of the present application with a key engaged. FIG. It is an expansion | deployment perspective view of the cutting tool shown in FIG. FIG. 3 is a side view of the cutting insert shown in FIGS. 1 and 2. It is a side view of the cutting insert by the 2nd Embodiment of this application. FIG. 3 is a side view of the holder blade shown in FIGS. 1 and 2. It is a side view of a holder blade according to a second embodiment of the present application. FIG. 2 is a side view of the cutting tool shown in FIG. 1 with the cutting insert positioned at the clamping position. FIG. 6 is a side view of a cutting tool according to a second embodiment of the present application, with a cutting insert located in a clamping position. FIG. 2 is a side view of the cutting tool shown in FIG. 1 with the cutting insert in the release position. FIG. 9 is a side view of the cutting tool shown in FIG. 8 with the cutting insert in the release position.

  [0010] It will be appreciated that for simplicity and clarity of illustration, the elements shown in the figures are not necessarily drawn to scale. For example, the dimensions of some elements are exaggerated relative to other elements for clarity, and some physical components may be included in one functional block or element. Further, where considered appropriate, reference numerals will be repeated among the figures to indicate corresponding or analogous elements.

Detailed Description of the Invention
[0011] In the following description, various aspects of the subject matter of the present application will be described. For purposes of explanation, specific configurations and details are set forth in sufficient detail to provide a thorough understanding of the subject matter of the present application. However, it will also be apparent to those skilled in the art that the subject matter of the present application may be practiced without the specific configuration and details presented herein.

  [0012] Attention is first directed to FIGS. 1 and 2, which show a cutting tool 20 of the type used for grooving or parting operations according to a first embodiment of the subject matter of the present application. The cutting tool 20 has a cutting insert 22 having an insert longitudinal axis A and a holder blade 24 having a holder longitudinal axis B, where the cutting insert 22 can be fixed to the holder blade 24 by a clamping force, and an extraction key 26 It can be taken out from the cutting tool 20 by rotation.

  [0013] Reference is now made to FIGS. The cutting inserts 22 and 122 have opposite insert upper and lower surfaces 28 and 30 together with a peripheral surface 32 extending therebetween. The cutting edge 34 is coupled to the insert upper surface 28. The peripheral surface 32 has two opposing outer surfaces 36.

[0014] The insert lower surface 30 includes at least one longitudinally extending lower clamp portion 52, wherein each lower clamp portion 52 is parallel to the insert longitudinal axis A and is joined to an insert virtual straight line L1 _I. , L2 _I. According to some embodiments of the present subject matter, the insert lower surface 30 may have two lower clamp portions 52, and the two respective insert virtual straight lines L1 _I , L2 _I are coaxial. There may be.

[0015] the insert passageway 38 extends along the insert passageway axis A _I, is open to the outer surface 36 opposed. The purpose of the insert passageway 38, the cutting insert 22, 122 is, as taken out from the insert receiving slot 42 by the rotation of the take-out key 26, in order to be able to apply the extraction force F _E, the projecting portion 40 of the take-out key 26 The object is to provide means for engaging the cutting inserts 22,122.

  [0016] According to some embodiments of the present subject matter, the insert passage 38 may open into the lower insert surface 30. According to other embodiments (not shown) of the subject matter of the present application, the insert passage 38 may not open into the lower insert surface 30. In such a configuration, the insert passage 38 is completely open to the outer surface 36. (Ie, the opening of the insert passage 38 is surrounded by the outer surface 36).

[0017] Inserts passage axis A _I contains an insert passage center point C _I. Throughout the description and claims, the use of the term “insert passage center point C _I ” is used in the side view of the cutting inserts 22, 122 between the insert horizontal and vertical lines H _I , V _I that bisect the insert passage 38. intersection and mentions, horizon H _I is parallel to the insert longitudinal axis a, I am the vertical line V _I which is perpendicular to the horizontal line H _I is will be appreciated. Vertical line V _I is located in the middle between the insert passageway forefront point and the rearmost point 44, 46 of the insert passage 38. The use of the terms “front” and “rear” throughout the description and the claims refers to the relative positions in FIGS. 3 to 10 in the direction of the insert and holder longitudinal axes A, B, generally facing left and right respectively. Will be understood correctly.

[0018] In some embodiments of the present invention the insert passage 38 is opened to insert lower surface 30, the horizontal line H _I, and the insert passage uppermost point 48 of the insert passage 38 lowermost insert virtual straight line L1 _I, L2 It is located in the middle of _I. In another embodiment (not shown), the horizontal line H _I is located in the middle between the insert passageway uppermost point and lowermost point 48 of the insert passage 38. Throughout the description and claims, the use of the terms “upper” and “lower” is relative to the direction perpendicular to the insert and holder longitudinal axes A, B, generally toward the top and bottom, respectively, in FIGS. It will be appreciated that the reference to location is correct.

[0019] According to some embodiments of the present subject matter, there may be exactly one insert passage 38. The insert passage 38 may include an insert bend 54 having a substantially constant radius with respect to the insert passage angle β _I. In such a configuration, the insert passage angle β _I may be greater than 90 °. Note that the radial center axis AR _I of the insert bend 54 does not necessarily have to be coaxial with the insert passage axis A _I.

[0020] the major plane P2 which is orientated perpendicular to the insert longitudinal axis A includes an insert passageway axis A _I. According to some embodiments of the present subject matter, the cutting inserts 22, 122 may exhibit mirror symmetry about the major plane P2.

  [0021] A third plane P3 that is flush with or parallel to the main plane P2 includes the insert passage uppermost point 48 and intersects the insert upper surface 28 at an intersection 55 in a side view of the cutting insert.

[0022] According to some embodiments of the present subject matter, in a side view of the cutting tool 20, 120 and measured in the third plane P3, an insert path uppermost point 48 on the insert path 38 and insert height between the passage height h1 between the lowermost insert virtual line _L1 I, L2 _I, measured in the third plane P3, the intersection point 55 and lowermost insert virtual line _L1 I, L2 _I It is at least a quarter of the size of h2. (That is, the maximum height of the insert passage 38 may be at least a quarter of the height of the cutting inserts 22, 122 when measured in the third plane P3.

Referring now to FIGS. 5 and 6, the holder blades 24, 124 have a body portion 56 and a holding portion 58. The holding portion 58 has two opposing side surfaces 60 and includes an insert receiving slot 42 that opens into the holder front end surface 62 of the holder blades 24, 124. The insert receiving slot 42 has a base jaw lower surface 64 facing in the upward direction U. Holder longitudinal axis B extends longitudinal direction _D F, the _{D R.} Holder passage 66 extends along the holder path axis A _H, are open on at least one of the two sides 60. According to some embodiments of the present subject matter, the holder passage 66 may extend between and open to both sides 60.

  [0024] According to some embodiments of the present subject matter, the holder passage 66 may open into the base jaw lower surface 64. According to other embodiments of the present subject matter, the holder passage 66 may not open into the base jaw lower surface 64. In such a configuration, the holder passage 66 is completely open to at least one of the side surfaces 60. (In other words, the opening of the holder passage 66 is surrounded by the side surface 60).

[0025] Holder passage axis A _H includes a holder passage center point C _H. Holder passage center point C _H is located below from the base jaw lower surface 64. Throughout the description and claims, the use of the term “holder path center point C _H ” is used in the side view of the holder blades 24, 124 between the holder horizontal and vertical lines H _H , V _H that bisect the holder path 66. It will be appreciated that reference is made to the point of intersection and that the holder horizontal line H _H is parallel to the holder longitudinal axis B and the holder vertical line V _H is perpendicular to the horizontal line H _H. The vertical line V _H is located in the middle of the holder passage 66 between the foremost point and the rearmost points 68 and 70 of the holder passage.

[0026] In some embodiments of the present invention in which the holder passage 66 is open to the base jaw lower surface 64, the horizontal line H _H is the holder passage lowermost point 74 of the holder passage 66 and the uppermost holder virtual straight line L1 _H , It is located midway between the L2 _H. In other embodiments in which the holder passage 66 is completely open to the side surface 60, the horizontal line H _H is located midway between the holder passage uppermost point and the lowermost points 72, 74 of the holder passage 38.

[0027] According to some embodiments of the present subject matter, the holder passage 66 may include a holder bend 76 having a substantially constant radius with respect to the holder passage angle β _H. The holder passage angle β _H may be greater than 90 °. The holder passage 66 may be circular in the side view of the cutting tools 20, 120. Radial center axis AR _H of the holder curved portion 76 should be necessarily noted that it is not a holder passage axis A _H coaxial.

[0028] The base jaw lower surface 64 includes at least one longitudinally extending base jaw clamp portion 78, wherein each base jaw clamp portion 78 is parallel to the holder longitudinal axis B and is a holder imaginary straight line L1 _H , it includes L2 _H.

[0029] According to some embodiments of the present subject matter, the base jaw lower surface 64 may have two base jaw clamps 78, two respective holder virtual straight lines L1 _H , L2 _H. May be coaxial.

  [0030] Referring now to FIGS. 7 and 8, at least one lower clamp portion 52 is in clamping contact with at least one base jaw clamp portion 78 (ie, in a clamping position), and the cutting insert 22, 122 is located at the rearmost position in the insert receiving slot 42 and defines an assembled state. When in the assembled state, the cutting tools 20, 120 are ready to perform a cutting operation. Due to the clamping contact between the lower clamp part 52 of the insert and the base jaw clamp part 78 of the holder blade, the cutting inserts 22, 122 and the holder blades 24, 124 are shown in the side view of the cutting tool 20, 120 in the side view of the cutting insert and A virtual boundary line LB that looks like the holder blades intersect is formed. However, the lower clamp part 52 of the insert and the base jaw clamp part 78 of the holder blade are usually provided with complementary surfaces such as a V-shaped groove part to be joined, so that the virtual boundary line LB is not necessarily limited to the cutting insert and the holder. It is well known that the actual abutment interface position with the blade need not be shown. As can be seen in FIGS. 7 and 8, the main plane P2 is perpendicular to the virtual boundary line LB.

[0031] The passage plane P1 including the holder passage and the insert passage axes A _H , A _I forms a first angle α with the main plane P2, and the first angle α is 60 ° or less. The holder longitudinal axis B is parallel to the insert longitudinal axis A.

[0032] According to some embodiments of the present subject matter, the first angle α may be 30 ° or less. Holder passage axis A _H may be in front of the insert passage axis A _I.

  [0033] According to a second embodiment (FIG. 8) of the subject matter of the present application, the main plane P2 may intersect the holder passage 66, and both inserts and holder passages 38, 66 are connected to the lower surface of the respective insert. 30 and the base jaw lower surface 64 may be opened. With this configuration, it is possible to use the take-out key 26 having only one protrusion 40.

  [0034] The insert receiving slot 42 may include a clamp jaw upper surface 80 that faces toward the base jaw lower surface 64, and the cutting inserts 22, 122 are elastic between the clamp jaw upper surface 80 and the base jaw lower surface 64. May also be clamped.

  [0035] According to some embodiments of the present subject matter, in the assembled state, the insert passage 38 and the holder passage 66 may not be occupied. Furthermore, in the assembled state, the insert passage 38 and the holder passage 66 may not be continuous at the insert passage frontmost point 44 and the holder passage frontmost point 68. The holder passage foremost point 68 may be located in front of the insert passage foremost point 44.

[0036] A subject aspect of the present application includes a method of removing the cutting inserts 22, 122 from the cutting tools 20, 120 by the removal key 26. That is, it includes adjusting the cutting inserts 22, 122 from the clamp position to the release position. Please refer to FIGS. The insert receiving slot 42 includes a clamp jaw upper surface 80 facing toward the base jaw lower surface 64, and the cutting inserts 22 and 122 are elastically clamped between the clamp jaw upper surface 80 and the base jaw lower surface 64. Yes. Extraction key 26 has at least one projection 40, at least one projecting portion 40 includes a first and second engagement portions 82, 84 and a single pivot A _P. Extraction key 26, the first and second engagement portions 82 and 84 respectively, to be engaged simultaneously in the holder passage 66 and the insert passageways 38 are positioned with respect to the cutting tool 20, 120, Axis _{A P} Is located in the holder passage 66. Extraction key 26 is rotated in one direction about the pivot _{A P,} applied to the cutting insert 22, 122 to take out force _{F E} in the previous direction _{D F.}

  [0037] After positioning the first and second engagement portions 82, 84 in the holder and insert passages 66, 38, respectively, a resisting downward force is located in the insert passage 38 during rotation of the retrieval key 26. At least one of the holder and insert passages 66, 38 is relative to at least one of the first and second engagement portions 82, 84 so that it is not created by the second engagement portion 84. Provides freedom to shift in a direction parallel to P1.

According to some embodiments of the [0038] This application subject matter, pivot A _P is the holder and the insert passage axis A _H, may be parallel to the A _I. The step of rotating the key 26 is taken out about a pivot axis A _P is provided between the second engaging portion 84 and the base jaw lower surface 64 or the holder passageway 66, it is executed until there is resistance contact that prevents further rotation Also good. In this position, the cutting inserts 22, 122 can be said to be in the release position, and the cutting inserts 22, 122 are no longer elastically clamped to the holding part 58.

  [0039] A feature of the subject matter of the present application is that a recess that accommodates the second engagement portion 84 of the removal key 26 at the rear of the insert receiving slot 42 when the cutting inserts 22, 122 are removed from the cutting tools 20, 120. Note that this is not necessary. The absence of a recess allows the clamp jaw upper surface 80 to have improved elastic force against the base jaw lower surface 64, thereby providing a greater magnitude of clamping force.

[0040] Another feature of the subject matter of the present application, the cutting insert 22, 122, removed from the cutting tool 20 and 120 using the extraction key 26, when applying the extraction force _{F E} on the insert passageway 38, the cutting insert 22 , 122 can be ejected from the insert receiving slot 42 in a controlled manner. When the take-out key 26 is rotated in the forward direction _DF in order to take out the cutting inserts 22 and 122, the second engaging portion 84 of the take-out key 26 is moved to the base jaw lower surface 64 or the holder passage 66 (see FIGS. 6 and 8). This is achieved because of the elastic contact. This contact prevents the removal key 26 from rotating further, and this contact occurs while the cutting inserts 22, 122 are partially positioned unchanged in the insert receiving slot 42. At this point, the removal key 26 can be released from the cutting tool 20, 120 so that the cutting insert 22, 122 can be completely removed from the holder blade 24, 124 in a controlled manner. For example, extraction force _{F E} is, when it is applied to the end surface of the farthest cutting insert from the cutting edge 34 22 122, the cutting insert 22, 122 will be liable to completely offset from the insert receiving slot 42. In such a scenario, for example, for a cutting insert 22 having the same shape at both ends, the tool operator cannot know which cutting edge 34 is used and which cutting edge 34 is not used.

  [0041] While the subject matter of the present application has been described with respect to certain degrees of characteristics, it is understood that various changes and modifications may be made without departing from the spirit or scope of the invention as claimed below. Needless to say.

Claims (22)

A holder blade (24, 124) and a cutting insert (22, 122) elastically clamped in the holder blade (24, 124), the holder blade (24, 124) being a body portion (56) And a holding part (58), the holding part (58) being a cutting tool (20, 120) having two opposing side faces (60),
An insert receiving slot (42) having a holder longitudinal axis (B) opening in the holder front end face (62) of the holder blade (24, 124) and extending in the front-rear direction (D _F , D _R );
A holder passage (66) extending along the holder passage axis (A _H ) and opening in at least one of the two side surfaces (60), wherein the holder passage axis (A _H ) is the center of the holder passage A holder passage (66) containing a point (C _H ),
The insert receiving slot (42) has a base jaw lower surface (64) facing upward (U), and the base jaw lower surface (64) is at least one base jaw clamp portion (in the longitudinal direction). 78), and each base jaw clamp portion (78) includes a holder virtual straight line (L1 _H , L2 _H ) parallel to the holder longitudinal axis (B),
The holder passage center point (C _H ) is located below the base jaw lower surface (64),
The cutting insert (22, 122) has an insert longitudinal axis (A) parallel to the holder longitudinal axis (B),
Including opposing insert upper and lower surfaces (28, 30) with a peripheral surface (32) extending therebetween, and a cutting edge (34) coupled to the insert upper surface (28), wherein the peripheral surface (32) Including two opposing outer faces (36);
The insert passage (38) extends along the insert passage axis (A _I ) and opens in the opposite outer surface (36), and the insert passage axis (A _I ) is inserted into the insert passage center point (C _I )
The insert lower surface (30) includes at least one longitudinally extending lower clamp portion (52), and each lower clamp portion (52) includes an insert virtual straight line (A) parallel to the insert longitudinal axis (A). L1 _I , L2 _I )
At least one lower clamp (52) is in clamping contact with the at least one base jaw clamp (78), and the cutting insert (22, 122) is the last in the insert receiving slot (42). It is located in the part position and defines the assembly state,
A passage plane (P1) including the holder passage axis (A _H ) and the insert passage axis (A _I ) is perpendicular to the insert longitudinal axis (A) and includes a main plane including the insert passage axis (A _I ). Forming a first angle (α) with P2),
The first angle (α) is 60 ° or less.
Cutting tools. The first angle (α) is 30 ° or less.
The cutting tool (20, 120) according to claim 1. The holder passage shaft (A _H ) is in front of the insert passage shaft (A _I );
The cutting tool (20, 120) according to claim 1 or 2. The holder passageway (66) extends between and opens to both sides (60);
The cutting tool (20, 120) according to any one of claims 1 to 3. There is exactly one insert passage (38),
The cutting tool (20, 120) according to any one of claims 1 to 4. The holder passage (66) includes a holder curvature (76) having a substantially constant radius with respect to the holder passage angle (β _H );
The insert passage (38) includes an insert bend (54) having a substantially constant radius with respect to the insert passage angle (β _I );
Both holder and insert passage angles (β _H , β _I ) are greater than 90 °,
The cutting tool (20, 120) according to any one of claims 1 to 5. The base jaw lower surface (64) has two base jaw clamps (78),
The two respective holder virtual straight lines (L1 _H , L2 _H ) are coaxial,
The cutting tool (20, 120) according to any one of claims 1 to 6. The insert passage (38) opens into the insert lower surface (30) and has an insert passage uppermost point (48).
The cutting tool (20, 120) according to any one of claims 1 to 7. A third plane (P3) that is the same plane as or parallel to the main plane (P2) includes the insert passage uppermost point (48). In the side view of the cutting insert, the upper surface of the insert ( 28)
In the side view of the cutting tool (20, 120) measured in the third plane (P3), between the insert passage uppermost point (48) and the lowermost insert virtual line (L1 _I , L2 _I ) The passage height (h1) is at least a quarter of the size of the insert height (h2) between the intersection (55) and the lowermost insert imaginary line (L1 _I , L2 _I ),
Cutting tool (20, 120) according to claim 8. The insert lower surface (30) has two lower clamp parts (52),
The two respective insert virtual lines (L1 _I , L2 _I ) are coaxial,
The cutting tool (20, 120) according to any one of claims 1 to 9. The insert receiving slot (42) includes a clamp jaw upper surface (80) facing toward the base jaw lower surface (64),
The cutting tool (20, 120) according to any one of claims 1 to 10. The insert passage (38) and the holder passage (66) are not occupied,
The cutting tool (20, 120) according to any one of claims 1 to 11. The insert passage (38) and the holder passage (66) are not continuous at the insert passage forward-most point (44) and the holder passage forward-most point (68).
The cutting tool (20, 120) according to any one of claims 1 to 12. The cutting insert (22) exhibits mirror symmetry about the main plane (P2).
The cutting tool (20) according to any one of claims 1 to 13. In the side view of the cutting tool (20), the holder passage (66) is circular,
Cutting tool (20) according to any one of the preceding claims. The holder passage (66) opens to the base jaw lower surface (64),
A cutting tool (120) according to claim 8. The main plane (P2) intersects the holder passage (66),
The cutting tool (120) according to any one of claims 1 to 16. The holder passage foremost point (68) is located in front of the insert passage foremost point (44),
The cutting tool (120) according to claim 13. A method for removing a cutting insert (24, 124) from a cutting tool (20, 120) by means of a removal key (26),
The cutting tool (20, 120) is the one according to any one of claims 1 to 18 ,
The insert receiving slot (42) includes a clamp jaw upper surface (80) facing toward the base jaw lower surface (64);
The cutting insert (22, 122) is elastically clamped between the clamp jaw upper surface (80) and the base jaw lower surface (64),
The take-off key (26) has at least one protrusion (40), the at least one protrusion (40) being a first and second engagement portion (82, 84) and a single pivot. (A _P )
The take-off key (26) is cut so that the first and second engaging portions (82, 84) are simultaneously engaged with the holder passage (66) and the insert passage (38), respectively. Positioning with respect to the tool (20, 120), the pivot (A _P ) being located in the holder passage (66);
Rotating the take-out key (26) in one direction around the pivot (A _P ) to apply a take-out force (F _E ) to the cutting insert (22, 122) in the forward direction (D _F ) Including,
Method. The pivot axis (A _P ) is parallel to the holder and insert passage axis (A _H , A _I ),
The method of claim 19. Until the resistance contact between the second engagement portion (84) and the lower surface of the base jaw (64) or the holder passage (66) prevents further rotation, the pivot (A _P ) is used as a center. Including rotating the eject key (26),
21. A method according to claim 19 or 20. Rotating the extraction key (26) about the pivot (A _P ) until the cutting insert (22, 122) is no longer elastically clamped to the retainer (58),
The method according to claim 19 or 21.

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